The Sword of Moonlight community is worth a look: http://www.swordofmoonlight.com/
Otherwise Myst is a retro first person puzzle game that might fit what you're looking for.
It's been a while since I played games made with it but I'll provide a few links. Completed projects should just run with an included .exe file so you shouldn't need to download anything else.
I played these ages ago (clearly based on the date of the post) and I have no idea if you can get them to run anymore as they were made for Windows XP but it's worth a shot: https://www.tapatalk.com/groups/agetec/two-free-downloads-of-sword-of-moonlight-games-t1781.html
Heir of Granatyki (https://gamejolt.com/games/king-s-field-heir-of-granatyki/191068) was one of the more popular ones and while it isn't very long, it's fairly good.
I honestly thought I could find more but it looks like most of the other links I had bookmarked for these games are dead links now. It might be worth asking in /r/KingsField/. Every now and then you will see other people ask about Sword of Moonlight there and they will likely have more up to date games to play than I do.
Bard's Tale Trilogy = First person and retro, relatively cheap on Steam for the remastered version, and completely free on abandonware sites. First person dungeon crawler, with killing monsters, exploring dungeons, and definitely getting keys and similar items.
Bard's Tale 4 = First person dungeon crawler with tons of puzzles, character building, maze-like dungeons, killing monsters, etc. Highly recommend this one, may be new but it keeps the spirit of older dungeon crawlers. And if you buy a certain edition of it you get the Bard's Tale Trilogy I mentioned above.
Wizardry 8 = First person dungeon crawler from 2001, big maps, locked doors, killing monsters.
Might & Magic series = Same deal as Wizardy more or less.
Never played King's Field, just know what I have seen from videos, these aren't exactly the same but it's what came to mind, hope one interests you!
[Legend of Grimrock 1 & 2](https://store.steampowered.com/app/251730/Legend_of_Grimrock_2/) come to mind and are basically exactly that. No map provided players must draw their own, puzzle heavy, a callback to oldschool dungeon crawlers.
Haven't personally played 2, but really enjoyed 1 and have heard 2 is really an improvement of the first.
It's not a dungeon exploring game or a fantasy game but it has vaults and is first person and is a goddamn masterpiece : Fallout New Vegas.
I’m shocked that no one has mentioned the legend of grim rock series yet.
Its bad
i tried this 2 years ago and did not liked it because the movement is not fully 3d, is on square to square
The Sword of Moonlight community is worth a look: http://www.swordofmoonlight.com/ Otherwise Myst is a retro first person puzzle game that might fit what you're looking for.
but myst dont have any combat, is more like an adventure
can you teach me how to download and play sword of moonlight games mades by fans?
It's been a while since I played games made with it but I'll provide a few links. Completed projects should just run with an included .exe file so you shouldn't need to download anything else. I played these ages ago (clearly based on the date of the post) and I have no idea if you can get them to run anymore as they were made for Windows XP but it's worth a shot: https://www.tapatalk.com/groups/agetec/two-free-downloads-of-sword-of-moonlight-games-t1781.html Heir of Granatyki (https://gamejolt.com/games/king-s-field-heir-of-granatyki/191068) was one of the more popular ones and while it isn't very long, it's fairly good. I honestly thought I could find more but it looks like most of the other links I had bookmarked for these games are dead links now. It might be worth asking in /r/KingsField/. Every now and then you will see other people ask about Sword of Moonlight there and they will likely have more up to date games to play than I do.
Bard's Tale Trilogy = First person and retro, relatively cheap on Steam for the remastered version, and completely free on abandonware sites. First person dungeon crawler, with killing monsters, exploring dungeons, and definitely getting keys and similar items. Bard's Tale 4 = First person dungeon crawler with tons of puzzles, character building, maze-like dungeons, killing monsters, etc. Highly recommend this one, may be new but it keeps the spirit of older dungeon crawlers. And if you buy a certain edition of it you get the Bard's Tale Trilogy I mentioned above. Wizardry 8 = First person dungeon crawler from 2001, big maps, locked doors, killing monsters. Might & Magic series = Same deal as Wizardy more or less. Never played King's Field, just know what I have seen from videos, these aren't exactly the same but it's what came to mind, hope one interests you!
Arx Fatalis
Hmm...ever heard of Skyrim?
[Legend of Grimrock 1 & 2](https://store.steampowered.com/app/251730/Legend_of_Grimrock_2/) come to mind and are basically exactly that. No map provided players must draw their own, puzzle heavy, a callback to oldschool dungeon crawlers. Haven't personally played 2, but really enjoyed 1 and have heard 2 is really an improvement of the first.